Help with Spot Metering
This is my first post, great forum you have here. The question that I have might have been asked, I did a search but I could not find the specific answer.
Can someone please explain (in steps) how spot metering is done using a camera which has inbuilt spot meter? I know this is a dumb question, but I am not looking for an answer explaining the concept of spot metering. I only want to know the steps of getting the right exposure using spot metering. Do I point at a part of the scene and take the meter reading? which reading is this? is it the shutter speed and appreture? I know these might be very basic newbie questions, but I would like to learn.
thank you :)
I think it demends on the type of film you are shooting, color or BW. I meter different with each.
On my dad's N90 (I have all manual cameras with no meters cuz I'm cheap) you put the camera in spot mode point at a subject and then depress the release half way. This focuses and holds the meter reading. When I use his camera I tend to put it in manual mode and meter the deepest shadows I want detail in, and then swing the camera around and repeat for the lightest area to get an idea of the SBR. If you are shooting Aperature priority or shutter priority then your reading will not be in EV's They will represent either the aperature and shutter speed appropriate for that metered area to print at around zone 5. If I use the auto modes then I usually stick with aperature prioity because I am more worried about DOF than shutter speed. That is what tripods were made for. Then I adjust accordingly depending on how dark I am wanting the shadows.
This is all just conjecture though. What does your readout say?
How best to use your camera's spot meter function really depends on the scene, the lighting, and what you want to accomplish or emphasize in the image. For example, if you are photographing a backlit person of average caucasian complexion, you could spot meter their face, and then open up 1 stop, or perhaps as much as 2 stops. In contrast, metering a moderate shadow area in a landscape, you might close down a stop or two. Metering green grass in a sunlit scene, you're probably safe in using that exposure directly.
Like any other typical meter, the spot meter in your camera will give you the exposure needed to render that area as a medium gray (or, the color equivalent). Knowing that, you can make adjustments as needed to get the tonality of the subject correct. Experimentation and note taking will help you nail future exposures.
The camera's manual should tell you what area of the viewfinder the spot meter covers. You can also test that by metering a white area surrounded by dark, noting where the meter reading starts to change.
first question you have to answer: what film type are you using, black and white, color negative (print film) or color slide? What you aim the meter at and how you adjust your settings will be different depending on the type of film you are using.
Here's how I use it on a Nikon in "Metered Manual" mode:
- Point the metering rectangle at the part of the scene I want to assess.
- Adjust the controls (speed or aperture) until the meter indicates the zone I want that element to fall on (It might read +2 for a white object, +1 for caucasian skin, -2 for dark shadows etc etc).
- Sweep the scene to check the exposure of the other elements in the scene. If the meter indicates more than +2 or less than -2, I'll assess whether I can live without those on my final tranny and make adjustments to the exposure if needed.
Your choice of film only dictates which end (+2 or -2) you choose as the most important part of the scene. The method of checking the scene doesn't change.
The purpose of the spot meter is to measure the contrast range of a scene. As mentioned before, depending on the type of film you are using you can best estimate the required cotrast range and exposure needed. For example, B&W film is capable of giving you printable information anywhere from 4 stops difference between dark and highlight to 8 stops or even 10 if you have done some testing and can adjust development. This is not the case with color film. With color film, be that negative or transparency you are limited by the development, which always has to be the same regardless of the contrast in your image.
For color film you can get away with about 5 o 6 stops contrast range, with transparency about 3 to 4 stops.
So the steps are, you take a measurement with your incamera spot meter of the dark part that you want to have detail, then you take a spot metering of the highlight, you see what is the difference in stops and use the metering from the dark part closing 2 stops from the recommended exposure (both aperture and shutter speed) Depending on the film you are using you will be able to determine whether you need devlopment controls or make a desicion as to have some elements go black without detail or go white without detail.